drm/xe/oa: Allow reading after disabling OA stream

Some OA data might be present in the OA buffer when OA stream is
disabled. Allow UMD's to retrieve this data, so that all data till the
point when OA stream is disabled can be retrieved.

v2: Update tail pointer after disable (Umesh)

Fixes: efb315d0a013 ("drm/xe/oa/uapi: Read file_operation")
Cc: stable@vger.kernel.org
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Reviewed-by: Umesh Nerlige Ramappa<umesh.nerlige.ramappa@intel.com>
Link: https://patch.msgid.link/20260313053630.3176100-1-ashutosh.dixit@intel.com

diff --git a/drivers/gpu/drm/xe/xe_oa.c b/drivers/gpu/drm/xe/xe_oa.c
index dcd393b0931a25d35f3a74581658250fa35110eb..2efc16c3a95df707507bd76fd332a63bcc5b8e3c 100644 (file)
--- a/drivers/gpu/drm/xe/xe_oa.c
+++ b/drivers/gpu/drm/xe/xe_oa.c
@@ -543,8 +543,7 @@ static ssize_t xe_oa_read(struct file *file, char __user *buf,
        size_t offset = 0;
        int ret;
 
-       /* Can't read from disabled streams */
-       if (!stream->enabled || !stream->sample)
+       if (!stream->sample)
                return -EINVAL;
 
        if (!(file->f_flags & O_NONBLOCK)) {
@@ -1456,6 +1455,10 @@ static void xe_oa_stream_disable(struct xe_oa_stream *stream)
 
        if (stream->sample)
                hrtimer_cancel(&stream->poll_check_timer);
+
+       /* Update stream->oa_buffer.tail to allow any final reports to be read */
+       if (xe_oa_buffer_check_unlocked(stream))
+               wake_up(&stream->poll_wq);
 }
 
 static int xe_oa_enable_preempt_timeslice(struct xe_oa_stream *stream)